Olfat El Sibai

A Novel Concept for the Surgical Anatomy of the Perineal Body

PurposePerineal body is considered by investigators as a fibromuscular structure that is the site of insertion of perineal muscles. We investigated the hypothesis that perineal body is the site across which perineal muscles pass uninterrupted from one side to the other.MethodsPerineal body was studied in 56 cadaveric specimens (46 adults, 10 neonatal deaths) by direct dissection with the help of magnifying loupe, fine surgical instruments, and bright light.ResultsPerineal body consisted of three layers: 1) superficial layer, which consisted of fleshy fibers of the external anal sphincter extending across perineal body to become the bulbospongiosus muscle; 2) tendinous extension of superficial transverse perineal muscle crossing perineal body to contralateral superficial transverse perineal muscle, with which it formed a criss-cross pattern; and 3) tendinous fibers of the deep transverse perineal muscle; the fibers crossing perineal body decussated in criss-cross pattern with the contralateral deep transverse perineal muscle. A relation of levator ani or puborectalis muscles to perineal body could not be identified.ConclusionsPerineal body (central perineal tendon) is not the site of insertion of perineal muscles but the site along which muscle fibers of these muscles and the external anal sphincter pass uninterrupted from one side to the other. Such a free passage from one muscle to the other seems to denote a “digastric pattern” for the perineal muscles. Perineal body is subjected to injury or continuous intra-abdominal pressure variations, which may eventually result in perineocele, enterocele, or sigmoidocele.

On the pathogenesis of penile venous leakage: role of the tunica albuginea

BackgroundEtiology of venogenic erectile dysfunction is not exactly known. Various pathologic processes were accused but none proved entirely satisfactory. These include presence of large venous channels draining corpora cavernosa, Peyronies disease, diabetes and structural alterations in fibroblastic components of trabeculae and cavernous smooth muscles. We investigated hypothesis that tunica albuginea atrophy with a resulting subluxation and redundancy effects venous leakage during erection.Methods18 patients (mean age 33.6 ± 2.8 SD years) with venogenic erectile dysfunction and 17 volunteers for control (mean age 31.7 ± 2.2 SD years) were studied. Intracorporal pressure was recorded in all subjects; tunica albuginea biopsies were taken from 18 patients and 9 controls and stained with hematoxylin and eosin and Massons trichrome stains.ResultsIn flaccid phase intracorporal pressure recorded a mean of 11.8 ± 0.8 cm H2O for control subjects and for patients of 5.2 ± 0.6 cm, while during induced erection recorded 98.4 ± 6.2 and 5.9 ± 0.7 cmH2O, respectively. Microscopically, tunica albuginea of controls consisted of circularly-oriented collagen impregnated with elastic fibers. Tunica albuginea of patients showed degenerative and atrophic changes of collagen fibers; elastic fibers were scarce or absent.ConclusionStudy has shown that during erection intracorporal pressure of patients with venogenic erectile dysfunction was significantly lower than that of controls. Tunica albuginea collagen fibers exhibited degenerative and atrophic changes which presumably lead to tunica albuginea subluxation and floppiness. These tunica albuginea changes seem to explain cause of lowered intracorporal pressure which apparently results from loss of tunica albuginea veno-occlusive mechanism. Causes of tunica albuginea atrophic changes and subluxation need to be studied.

An Electrophysiologic Study of Female Ejaculation

Opinions vary over whether female ejaculation exists or not. We investigated the hypothesis that female orgasm is not associated with ejaculation. Thirty-eight healthy women were studied. The study comprised of glans clitoris electrovibration with simultaneous recording of vaginal and uterine pressures as well as electromyography of corpus cavernous and ischio- and bulbo-cavernosus muscles. Glans clitoris electrovibration was continued until and throughout orgasm. Upon glans clitoris electrovibration, vaginal and uterine pressures as well as corpus cavernous electromyography diminished until a full erection occurred when the silent cavernosus muscles were activated. At orgasm, the electromyography of ischio-and bulbo-cavernosus muscles increased intermittently. The female orgasm was not associated with the appearance of fluid coming out of the vagina or urethra.

Diverticular Disease: Electrophysiologic Study and a New Concept of Pathogenesis

The cause of diverticular disease (DD) is not exactly known, although colonic motor disorder has been proposed as a factor in the pathogenesis of the condition. We investigated the hypothesis that disordered colonic electrical activity is responsible for the colonic motor dysfunction and the development of DD. The electromyographic (EMG) activity and pressure of the sigmoid colon (SC) were recorded in 36 patients [16 early cases, 20 advanced cases; age (mean ± SD) 53.3 ± 5.6 years; 19 women, 17 men] and 22 healthy volunteers. The percutaneous route was used for recording the SC EMG. The healthy volunteers exhibited SC slow waves with a regular rhythm and the same frequency, amplitude, and conduction velocity from the three electrodes in the same subject. The SC basal pressure (7.9 cm H2O) was interrupted by bouts of high pressure (26.8 cm H2O). The early-DD cases showed slow waves with an irregular rhythm and significantly higher variables (p < 0.05) than the volunteers. Action potentials followed randomly or were superimposed on the slow waves. The SC basal pressure was significantly higher than that of the volunteers (21.4 cm H2O, p < 0.01). Bouts of pressure (58.6 cm H2O) coupled with action potentials were recorded. No waves were recorded from 15 of 20 of the advanced-DD patients. In 5 patients, slow waves with an irregular rhythm and lower variables (p < 0.05) than those of the volunteers were recorded. The basal SC pressure was significantly above normal. Three electrical activity patterns could be identified in DD patients: “tachyrhythmic” in the early-DD patients and “bradyrhythmic” or “silent” in the late-DD patients. These dysrhythmias may result from a disordered colonic pacemaker. The similarity between early DD and the irritable bowel syndrome suggests that DD is an advanced stage of the irritable bowel syndrome; studies are required to investigate this hypothesis further.

Percutaneous perineal electrostimulation induces erection: clinical significance in patients with spinal cord injury and erectile dysfunction.

Abstract Objectives: Approximately one third to one half of the penis is embedded in the pelvis and can be felt through the scrotum and in the perineum. The main arteries and nerves enter the penis through this perineal part of the penis, which seems to represent a highly sensitive area. We investigated the hypothesis that percutaneous perineal stimulation evokes erection in patients with neurogenic erectile dysfunction. Methods: Percutaneous electrostimulation of the perineum (PESP) with synchronous intracorporeal pressure (ICP) recording was performed in 28 healthy volunteers (age 36.3 ± 7.4 y) and 18 patients (age 36.6 ± 6.8 y) with complete neurogenic erectile dysfunction (NED). Current was delivered in a sine wave summation fashion. Average maximal voltages and number of stimulations delivered per session were 15 to 18 volts and 15 to 25 stimulations, respectively. Results: PESP of healthy volunteers effected an ICP increase (P < 0.0001), which returned to the basal value upon stimulation cessation. The latent period recorded was 2.5 ± 0.2 seconds. Results were reproducible on repeated PESP in the same subject but with an increase of the latent period. Patients with NED recorded an ICP increase that was lower (P < 0.05) and a latent period that was longer (P < 0.0001) than those of healthy volunteers. Conclusion: PESP effected ICP increase in the healthy volunteers and patients with NED. The ICP was significantly higher and latent period shorter in the healthy volunteers than in the NED patients. PESP may be of value in the treatment of patients with NED, provided that further studies are performed to reproduce these results.

The Effect of Esophageal and Gastric Distension on the Crural Diaphragm

The mechanism of prevention of gastric reflux into the esophagus is not exactly known. The lower esophagus has a barrier function provided by the lower esophageal sphincter. We investigated the hypothesis that the crural diaphragm shares in the barrier function not only mechanically but also actively through a crural–esophageal–gastric reflex action. The study was performed during repair of abdominal ventral and incisional hernias in 20 subjects (11 men, 9 women; age 38.6 ± 4.8 years). The electromyographic response of the crural diaphragm to individual balloon distension of esophagus and stomach was recorded by means of a needle electrode inserted into the crural diaphragm and connected to an electromyographic apparatus. The recordings were repeated after separate crural, esophageal, and gastric anesthetization. The crural diaphragm exhibited basal motor unit action potentials, which decreased on esophageal distension (P < 0.001) after a mean latency of 17.3 ± 2.8 SD ms. The crural diaphragm response to esophageal distension did not occur after the crural diaphragm or esophagus was anesthetized. Gastric distension effected an increase of crural diaphragm electromyographic activity with a mean latency of 18.4 ± 4.6 ms; this effect could not be achieved after the crural diaphragm or stomach was anesthetized. The crural diaphragm has a resting tone that relaxes after esophageal distension and contracts after gastric distension. This sphincter-like action of the crural diaphragm appears to be a reflex and is mediated through the esophagocrural inhibitory and gastrocrural excitatory reflexes. The crural diaphragm seems to share actively in the gastroesophageal competence mechanism.

Effect of Urethral Stimulation on Vesical Contractile Activity

Background:We investigated the hypothesis that urethral stimulation effects vesical contraction. Methods:Vesical pressure response to urethral balloon distension with normal saline in increments of 1 mL was recorded in 26 healthy volunteers (17 men, 9 women; mean age, 36.9 ± 9.7 SD years) before and after individual anesthetization of the urinary bladder and urethra. Urethral distension was effected by a 6F balloon-ended catheter introduced per urethra. Vesical pressure was measured by means of a microtip catheter. Results:Vesical pressure recorded gradual increase on increase of urethral balloon distension. Bladder response was maintained as long as urethral distension was continuous. The response showed no significant difference when we distended different parts of the male or female urethrae. Urethral distension after individual vesical and urethral anesthetization effected no change in the vesical pressure. Conclusions:Urethral distension produced a vesical pressure increase that presumably denotes vesical contraction. Vesical contraction on urethral stimulation by distension is suggested to be mediated through a “urethrovesical stimulating reflex” that seems to facilitate vesical contraction. Provided further studies to be performed in this respect, the reflex may prove to be of diagnostic significance in micturition disorders.

The identification of specialized pacemaking cells in the anal sphincters

Background and aimsInterstitial cells of Cajal (ICC) are claimed to generate the electrical activity in the colon and stomach. As the external (EAS) and internal (IAS) anal sphincters exhibit resting electrical activity, we hypothesized the presence of ICC in these sphincters. This hypothesis was investigated in the current study.Patients/MethodsSpecimens from the EAS and IAS were taken from normal areas of the anorectum which had been surgically excised by abdominoperineal operation for rectal cancer of 28 patients (16 men, 12 women, mean age 42.2±4.8 years). The specimens were subjected to c-kit immunohistochemistry. Controls for the specificity of the antisera consisted of tissue incubation with normal rabbit serum substituted for the primary antiserum.Results/FindingsFusiform, c-kit positive, ICC-like cells were detected in the anal sphincters; they had dendritic processes. They were clearly distinguishable from the non-branching, c-kit negative smooth and striated muscle cells of the anal sphincters. The specimens contained also c-kit positive mast cells, but they had a rounded body with no dendritic processes. Immunoreactivity was absent in negative controls in which the primary antibody was omitted.Interpretation/ConclusionWe have identified, for the first time, cells in EAS and IAS with morphological and immunological phenotypes similar to ICCs of the gut. These cells appear to be responsible for initiating the slow waves recorded from the anal sphincters and for controlling their activity. A deficiency or absence of these cells may affect the anal motile activity. Studies are needed to explore the role of these cells in anal motility disorders.

Contraction of Gluteal Maximus Muscle on Increase of Intra-Abdominal Pressure: Role in the Fecal Continence Mechanism:

The gluteus maximus muscle (GMM) appears to contract with increased intra-abdominal pressure (IAP). The hypothesis that GMM contraction with increased IAP was investigated. The study comprised 32 healthy volunteers. IAP was measured by intravesical catheter. The response of electromyography of the GMM and external anal sphincter to sudden momentary and slow sustained straining was registered. The procedure was repeated after individual urinary bladder and GMM anesthetization. Sudden straining increased electromyographic activity of the external anal sphincter and GMM. Slow, sustained straining raised electromyographic activity of the gluteus maximus and external sphincter at differing degrees depending on straining intensity. The anesthetized gluteus maximus or urinary bladder did not respond to straining. The suggested GMM contraction on straining seems mediated through a reflex that is called “straining-gluteal reflex.” This reflex appears to assist anal closure through extended and laterally rotated femur induced by gluteus contraction.

Physioanatomical relationship of the external anal sphincter to the bulbocavernosus muscle in the female

Both external anal sphincter (EAS) and bulbocavernosus muscle (BCM) have been shown anatomically and physiologically to constitute one muscle in males. We investigated the hypothesis that the EAS and BCM have similar anatomical pattern in females. The study consisted of cadaveric dissection, electromyographic recordings and inferior rectal nerve stimulation. Bulbocavernosus reflex action was performed in 16 healthy women before and after anesthetization of the EAS and BCM. The EAS extended forward across the perineal body and became continuous with the BCM in the labia majora. Glans clitoris (GC) or inferior rectal nerve stimulation effected synchronous EAS and BCM contractions with identical action potentials. GC stimulation while the EAS or BCM was anesthetized produced neither EAS nor BCM response. Similarly, stimulation of the anesthetized GC produced no EAS or BCM response. The BCM and EAS apparently constitute a single muscle, which seems to play dual and yet synchronous roles in fecal control and sexual response.